Usage of an indented bullet does not imply the statement is a response.

Brown Ben Plumm's ancestors

Brown Ben Plumm's ancestry is still somewhat unclear. He believes himself to be descended from one of the Targaryen princesses during the reign of one of the Aegon Targaryen Kings (probably Aegons II to IV, since he is unlikely to be descended from one of Aegon I's sisters and Aegon V ruled a bit too recently). Tyrion believes him to have "two drops of dragon blood", which would imply Targaryen ancestry by some other way as well.

If Tyrion is correct, a strong possibility is that he is descended from Ossifer Plumm and his wife the Targaryen princess believed to be Elaena Targaryen. She was Aegon III Targaryen the Dragonbane's youngest daughter. As there are rumours that Ossifer's wife conceived "his" child after his death, the reference to "two drops" of dragon blood may mean that Tyrion suspects Ossifer's wife to have fathered the child with another Targaryen -- possibly the ever-promiscuous Aegon IV Targaryen.

Another strong possibility is that he is descended from Maynard Plumm, a character from The Mystery Knight that apparently works for Bloodraven. Bloodraven himself is a legitimized bastard from Aegon IV and it is conceivable that he may have sired children that at some point had children of their own with Maynard's.

Maynard is believed by many fans to have actually been Bloodraven himself, glamoured. This due to the remarks Maynard makes:

“

Dunk:"We'd all be bastard sons of old King Aegon if half these tales were true."Maynard Plumm:"And whose to say we're not?"

”

.

In addition, Maynard seems to have been glamoured, if the description of Maynard given by Dunk at the end of the novella The Mystery Knight' is compared with the description of glamouring by Melissandre, in the novel A Dance with Dragons.

Bloodraven may have sired children as Maynard Plumm, so the children would claim the surname Plumm.